I'm playing around with a design for an RC size airplane (probably 7-8' wing span by the time I'm done with everything.) Right now I just have the wings squared off at the ends, but it would be really cool to be able to draw up some futuristic winglets. Here are a few examples of the sorts of things I'm talking about.

http://catalina.flightgear.org/curt/PhotoAlbums/2008%20EAA%20Air%20Venture/EAA%20Winglets/

I'm pretty new to MoI and not a super skilled 3d modeler. I took a couple random stabs in the dark to see if I could make something work, but so far I haven't been able to come up with much. So I just thought I'd ask here to see if anyone has any good ideas for how I could approach this?

I have curves that define that airfoil shape (the last wing rib at the tip of the wing) .... I have to match up to that. But I don't have a specific winglet design that I'm married too, anything outboard of the last wing rib I can pretty much freeform however I want to make it look cool.

If I could figure out some basic strategies for creating/blending/extruding? the winglet then I figure I can play around from there.

Thanks,

Curt.

Hi Curt, one possible method is to use the Sweep tool to build a wing like that.

You'd do something like have some kind of profile curve like this:



Then draw some rail curves that come away from that profile and swoop upwards and also backwards as well, like this:



Then you can select the profile, and then run the Construct > Sweep command, and then pick those 2 up-swooping curves as the rails. That will basically create a shape by dragging that starting profile between those rails, giving you a result like this:



I've attached a 3DM file with those curves in it if you want to take a closer look at them.

One trick is building the swoopy curves, since they kind of bend around in 3D and are not just 2D curves. One method for constructing curves like that is to start out with a curve that you draw in the Front view that has kind of a basic 90 degree bend in it, then turn on the control points (select the curve and push the "Edit > Show pts" button) and select these points here:



And then switch to the Top view and drag just those particular points backwards to give it some of the 3D bending shape. You may also make some adjustments to just 1 particular point a time. But basically switching to a different view and then dragging some points around is a pretty good method for making curves shaped like that.

Hope this helps get you started,

- Michael

Hi Curt, so also you wrote:

> If I could figure out some basic strategies for
> creating/blending/extruding? the winglet then I figure
> I can play around from there.

Extrude is for making a shape that just goes out straight in one direction.

For something that isn't just straight and kind of bends around, Sweep or Network tend to be the tools to use for stuff like that if you want to build it all as one surface, and sweep can be a bit easier to set up than Network.

Blend is more for creating a connector piece in between 2 existing surfaces.

It can be possible to create bendy stuff with Blend though too - the way that works is you would build 2 sections of the shape using some other tools, like here are 2 extrusions with one having been rotated into a different position:



Then Blend can be used to make a connector piece between them:



This is quite a bit more difficult to control though, and the resulting shape doesn't have quite the same kind of continuous gradual change that something like a sweep will have. So more often you would probably try to draw some guide curves to shape the sweep like in the previous post.

Sweep can be finicky in the spots where you collapse the rails together, it's fairly easy for the resulting surface to get sort of bunched up in those areas if the rails don't come together very well like if one rail is substantially longer than the other or things like that. So usually you don't want the rail curves to be too tremendously different from each other - the profile slides along them and if one curve is a lot longer than the other then that end of the profile is kind of sliding along faster than the other one, and you can get some bunching up along the side that is going slower.

- Michael

Hi Michael,

Thanks for the detailed suggestions and help. I played around with a bit with all this last night and it seemed like I had the best luck with the sweep command. Just messing around with the shapes and curves a bit, here is what I came up with. Still impressed with how quick and intuitive it can be in MoI to build complex stuff!

Thanks,

Curt.

Cool form!

Seing your thick's curves, seems you have some curves overlaped?